Mr. Nance,
On the Square of Opposition, the particular affirmative is “Some S is P” and the particular negative is “Some S is not P.” Why does the universal “All S is P” not have the contrary universal “All S is not P”? Why instead do you use “No S is P”?
Just curious! Continue reading Logic and Biblical Ambiguities
“A man who uses a great many words to express his meaning is like a bad marksman who, instead of aiming a single stone at an object, takes up a handful and throws at it in hopes he may hit.” – Samuel Johnson
“The three secrets of success in public speaking are: Be sincere, be brief, be seated.” – Franklin D. Roosevelt
“Learn to hold thy tongue; five words cost Zacharias forty weeks of silence.” – Thomas Fuller
Logic may be considered as a symbolic language which represents the reasoning inherent in other languages. It does so by reducing the language of statements and arguments down into symbolic form, simplifying them such that the arrangement of the language, and thus the reasoning within it, becomes apparent. The extraneous parts of statements are removed like a biology student in the dissection lab removes the skin, muscles and organs of a frog, revealing the skeleton of bare reasoning inside.
Mr. Nance,
In the Introductory Logic video Lesson 12, you write this sentence on the white board: “Some days the sun just doesn’t shine.” The first rule to put this sentence into the proper form states: Identify and write the complete subject. You identified “days” as the subject. Essentials taught me to ask, “Who or what does (not) shine?” Doesn’t that mean that “the sun” is the subject? How imperative is it that the subject be identified correctly? Continue reading Categorical form & getting the subject right
Mr. Nance,
In the Intro Logic course, the answer guide shows that a past tense statement, “God created heaven and earth” was converted to the present tense, “God is the Creator of heaven and earth.” I clearly see that the subject of the sentence (God) is like no other subject…is that why? Or would you have done this with a similar sentence? “Jane Austen authored Pride and Prejudice.” –> “Jane Austen is the author of Pride and Prejudice.” (I am wondering if you have an exception to the Caution printed on the previous page.) Thank you!
“Sacred cows make the best hamburger.” – Mark Twain
“Ending a sentence with a preposition is something up with which I will not put.” – Winston Churchill
“In theory there ain’t no difference between theory and practice. In practice there is.” – Yogi Berra
Mr. Nance,
1. Where does the A E I O come from for the four categorical statement types?
These are simply the first four vowels in English. I have been told that A and I come from the Latin “Affirmo” and the E and O from the Latin “Nego,” but I cannot confirm this.
2. If two statements say “Red is my favorite color” and “All my shirts are red” is their relationship independence or implication? Continue reading On Relationships Between Statements
A statement is a sentence that has a truth value, either true or false. Several types of sentences are not statements – questions and commands, for instance – because they do not have truth values. Another type of sentence that is not a statement can be called nonsense.
Nonsense sentences are not statements for the same reason as questions and commands; they cannot be said to be true or false. There are two types of nonsense sentences that we usually encounter in studies of logic. Continue reading Everything I say is a lie
Mr. Nance,
I remember one technique you employed in logic class to teach enthymemes was the citation of examples of these in scripture. Have you ever used John 18:30? “They answered and said unto him, ‘If he were not a malefactor, we would not have delivered him up unto thee.’ ” Does that combine an enthymeme and a hypothetical syllogism? Continue reading Enthymeme in John 18:30?